Accelerated Approval of Aducanumab: Where Do We Stand Now?

Aducanumab was approved by the Food and Drug Administration (FDA) in June 2021 to treat Alzheimer disease (AD). Its path to approval has been highly scrutinized, with many experts arguing that the FDA's decision was premature. Accelerated approval was based on a surrogate end point, with evidence to support clinical effectiveness pending a postapproval trial by the drug company sponsor Biogen. As a result, the role of aducanumab in treating AD remains uncertain. A summary of key areas of controversy to guide informed decisions about use of this drug is provided, along with a timeline describing preapproval and postapproval events.